101-85-9Relevant articles and documents
Porous, Naturally Derived Hafnium Phytate for the Highly Chemoselective Transfer Hydrogenation of Aldehydes with Other Reducible Moieties
Song, Jinliang,Xue, Zhimin,Xie, Chao,Wu, Haoran,Liu, Shuaishuai,Zhang, Lujun,Han, Buxing
, p. 725 - 730 (2018)
Both the utilization of naturally occurring compounds to prepare functional materials and the selective conversion of aldehydes with other reducible moieties (ORMs) are very attractive topics. Herein, we synthesized a novel porous material, hafnium phytate (Hf-Phy), by using naturally derived sodium phytate as the building block. Hf-Phy has plenty of mesopores centered around 11.8 nm. Hf-Phy showed excellent performance for the transfer hydrogenation of aldehydes with ORMs by using 2-propanol as the hydrogen source with high selectivities (95–100 %) for alcohols without reducing ORMs. Systematic studies suggested that the oxophilicity of Hf4+ and the basicity and structure of Hf-Phy contributed significantly to the excellent performance. Additionally, Hf-Phy could be used over at least five cycles without any decrease in activity or selectivity.
Post-synthesized zirconium-containing Beta zeolite in Meerwein-Ponndorf-Verley reduction: Pros and cons
Wang, Jie,Okumura, Kazu,Jaenicke, Stephan,Chuah, Gaik-Khuan
, p. 112 - 120 (2015)
Zr-Beta zeolite was prepared by a two-step post-synthesis method involving dealumination of Al-Beta followed by wet impregnation with Zr(NO3)4. Compared with Zr-Beta formed under fluoride-mediated hydrothermal conditions, the post-synthesized samples had smaller particle size and stronger Lewis acidity. The materials were tested as catalysts for Meerwein-Ponndorf-Verley reduction. In the reduction of 4-tert-butylcyclohexanone, it exhibited the same excellent stereoselectivity toward cis-4-tert-butylcyclohexanol (>99%) as the HF-synthesized Zr-Beta, but had a lower TOF. Because of the higher density of zirconium sites and the nanosized crystallites, it was a more effective catalyst for the MPV reduction of 1,4-cyclohexanedione, bulky aldehydes and aromatic ketones. However, it is more susceptible to poisoning by water adsorption because of its hydrophilic nature. The easily scalable synthesis method allows a faster preparation of metal-substituted Lewis acid zeolites, although differences in textural and chemical properties should be taken into consideration when the material is applied as a catalyst.
Imine Nitrogen Bridged Binuclear Nickel Complexes via N-H Bond Activation: Synthesis, Characterization, Unexpected C,N-Coupling Reaction, and Their Catalytic Application in Hydrosilylation of Aldehydes
Wang, Lin,Sun, Hongjian,Li, Xiaoyan
, p. 5175 - 5182 (2015)
The reactions of NiMe2(PMe3)3 with 2,6-difluoroarylimines were explored. As a result, a series of binuclear nickel complexes (5-8, 11) were synthesized. Meanwhile, from the reactions of NiMe2(PMe3)3 with [2-CH3C6H4-C(=NH)-2,6-F2C6H3] (9) and [2,6-(CH3)2C6H3-C(=NH)-2,6-F2C6H3] (10), two unexpected C,N-coupling products (12 and 13) were obtained. It is believed that these coupling reactions underwent activation of the N-H and C-F bonds. The binuclear nickel complexes showed excellent catalytic activity in the hydrosilylation of aldehydes. The mechanism of the reaction was studied through stoichiometric reactions, and the double-(η2-Si-H)-NiII intermediate was detected by in situ 1H NMR spectroscopy, which may be the key point in the catalytic cycle.
Fast and selective iron-catalyzed transfer hydrogenations of aldehydes
Wienh?fer, Gerrit,Westerhaus, Felix A.,Junge, Kathrin,Beller, Matthias
, p. 156 - 159 (2013)
An efficient iron-based catalyst system consisting of Fe(BF)4$6H2O and P(CH2CH2PPh2)3 [tetraphos, (PP3)] is presented for the highly selective transfer hydrogenation of aromatic, aliphatic, and a,b-unsaturated aldehydes. A wide range of substrates including aldehydes with other reducible functional groups gave the corresponding alcohols in good yields. Formic acid is applied as a cheap, environmentally benign and easy to handle hydrogen source. Notable features of the presented methodology are the fast reactions under mild conditions. Advantageously compared to most transfer hydrogenations, no stoichiometric amounts of base additives are required.
Chemoselective transfer hydrogenation of α,β-unsaturated carbonyl compounds using potassium formate over amine-grafted Ru/AlO(OH) catalysts
Gao, Yanxiu,Wang, Jie,Han, Aijuan,Jaenicke, Stephan,Chuah, Gaik Khuan
, p. 3806 - 3813 (2016)
Grafting of 3-(2-aminoethylamino)propyltrimethoxysilane onto Ru/AlO(OH) resulted in an active and highly chemoselective heterogeneous catalyst for the transfer hydrogenation of α,β-unsaturated carbonyl compounds to the corresponding allylic alcohols. Potassium formate was used as a sustainable hydrogen donor. A range of substrates including cinnamaldehyde, α-amylcinnamaldehyde, citral, 3-methyl-2-butenal, trans-2-pentenal, and trans-hexenal were selectively hydrogenated at the CO moiety with >96% selectivity. In comparison, the unmodified 1 wt% Ru/AlO(OH) catalyzed hydrogenation of cinnamaldehyde at the CC bond, yielding 3-phenylpropanal as the product. Higher loaded samples with 2-10 wt% Ru exhibited 20-25% selectivity to cinnamyl alcohol. The results show that low coordination sites were more selective to hydrogenation of the internal CC than the terminal CO bond. Immobilization of the amine via chemical bonding with hydroxyl groups of the AlO(OH) support blocks adjacent exposed metal sites, increasing the chemoselective reduction of CO. Optimum results were achieved at an amine/Ru ratio of 6. The catalyst maintained high activity and chemoselectivity even after five cycles.
Copper(i) pyrimidine-2-thiolate cluster-based polymers as bifunctional visible-light-photocatalysts for chemoselective transfer hydrogenation of α,β-unsaturated carbonyls
Zhang, Meng Juan,Young, David James,Ma, Ji Long,Shao, Guo Quan
, p. 14899 - 14904 (2021)
The photoinduced chemoselective transfer hydrogenation of unsaturated carbonyls to allylic alcohols has been accomplished using cluster-based MOFs as bifunctional visible photocatalysts. Assemblies of hexanuclear clusters [Cu6(dmpymt)6] (1, Hdmpymt = 4,6-dimethylpyrimidine-2-thione) as metalloligands with CuI or (Ph3P)CuI yielded cluster-based metal organic frameworks (MOFs) {[Cu6(dmpymt)6]2[Cu2(μ-I)2]4(CuI)2}n (2), {[Cu6(dmpymt)6]2[Cu2(μ-I)2]4}n (3), respectively. Nanoparticles (NPs) of 2 and 3 served both as photosensitizers and photocatalysts for the highly chemoselective reduction of unsaturated carbonyl compounds to unsaturated alcohols with high catalytic activity under blue LED irradiation. The photocatalytic system could be reused for several cycles without any obvious loss of efficiency.
Allylic alcohol synthesis by Ni-catalyzed direct and selective coupling of alkynes and methanol
Chen, Herong,Kong, Wangqing,Zhou, Zhijun
, p. 9372 - 9378 (2021/07/25)
Methanol is an abundant and renewable chemical raw material, but its use as a C1 source in C-C bond coupling reactions still constitutes a big challenge, and the known methods are limited to the use of expensive and noble metal catalysts such as Ru, Rh and Ir. We herein report nickel-catalyzed direct coupling of alkynes and methanol, providing direct access to valuable allylic alcohols in good yields and excellent chemo- and regioselectivity. The approach features a broad substrate scope and high atom-, step- and redox-economy. Moreover, this method was successfully extended to the synthesis of [5,6]-bicyclic hemiacetals through a cascade cyclization reaction of alkynones and methanol.
Ambient-pressure highly active hydrogenation of ketones and aldehydes catalyzed by a metal-ligand bifunctional iridium catalyst under base-free conditions in water
Wang, Rongzhou,Yue, Yuancheng,Qi, Jipeng,Liu, Shiyuan,Song, Ao,Zhuo, Shuping,Xing, Ling-Bao
, p. 1 - 7 (2021/05/17)
A green, efficient, and high active catalytic system for the hydrogenation of ketones and aldehydes to produce corresponding alcohols under atmospheric-pressure H2 gas and ambient temperature conditions was developed by a water-soluble metal–ligand bifunctional catalyst [Cp*Ir(2,2′-bpyO)(OH)][Na] in water without addition of a base. The catalyst exhibited high activity for the hydrogenation of ketones and aldehydes. Furthermore, it was worth noting that many readily reducible or labile functional groups in the same molecule, such as cyan, nitro, and ester groups, remained unchanged. Interestingly, the unsaturated aldehydes can be also selectively hydrogenated to give corresponding unsaturated alcohols with remaining C=C bond in good yields. In addition, this reaction could be extended to gram levels and has a large potential of wide application in future industrial.
Method for synthesizing unsaturated primary alcohol in water phase
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Paragraph 0034-0035, (2021/07/14)
The invention discloses a method for synthesizing unsaturated primary alcohol in a water phase. The method comprises the following steps: taking unsaturated aldehyde as a raw material, selecting water as a solvent, and carrying out catalytic hydrogenation reaction on the unsaturated aldehyde in the presence of a water-soluble catalyst to obtain the unsaturated primary alcohol, wherein the catalyst is a metal iridium complex [Cp * Ir (2, 2'-bpyO)(OH)][Na]. Water is used as the solvent, so that the use of an organic solvent is avoided, and the method is more environment-friendly; the reaction is carried out at relatively low temperature and normal pressure, and the reaction conditions are mild; alkali is not needed in the reaction, so that generation of byproducts is avoided; and the conversion rate of the raw materials is high, and the yield of the obtained product is high. The method not only has academic research value, but also has a certain industrialization prospect.and.
Microwave-heated γ-Alumina Applied to the Reduction of Aldehydes to Alcohols
Dhokale, Bhausaheb,Susarrey-Arce, Arturo,Pekkari, Anna,Runemark, August,Moth-Poulsen, Kasper,Langhammer, Christoph,H?relind, Hanna,Busch, Michael,Vandichel, Matthias,Sundén, Henrik
, p. 6344 - 6355 (2020/10/28)
The development of cheap and robust heterogeneous catalysts for the Meerwein-Ponndorf-Verley (MPV) reduction is desirable due to the difficulties in product isolation and catalyst recovery associated with the traditional use of homogeneous catalysts for MPV. Herein, we show that microwave heated γ-Al2O3 can be used for the reduction of aldehydes to alcohols. The reaction is efficient and has a broad substrates scope (19 entries). The products can be isolated by simple filtration, and the catalyst can be regenerated. With the use of microwave heating, we can direct the heating to the catalyst rather than to the whole reaction medium. Furthermore, DFT was used to study the reaction mechanism, and we can conclude that a dual-site mechanism is operative where the aldehyde and 2-propoxide are situated on two adjacent Al sites during the reduction. Additionally, volcano plots were used to rationalize the reactivity of Al2O3 in comparison to other metal oxides.
